Gas phase etching system and method

ABSTRACT

A method and system for the dry removal of a material on a microelectronic workpiece are described. The method includes receiving a workpiece having a surface exposing a target layer to be at least partially removed, placing the workpiece on a workpiece holder in a dry, non-plasma etch chamber, and selectively removing at least a portion of the target layer from the workpiece. The selective removal includes operating the dry, non-plasma etch chamber to perform the following: exposing the surface of the workpiece to a chemical environment at a first setpoint temperature in the range of 35 degrees C. to 100 degrees C. to chemically alter a surface region of the target layer, and then, elevating the temperature of the workpiece to a second setpoint temperature at or above 100 degrees C. to remove the chemically treated surface region of the target layer.

FIELD OF INVENTION

The invention relates to a dry non-plasma treatment system and methodfor treating a substrate, and more particularly to a dry non-plasmatreatment system and method for chemical and thermal treatment of asubstrate.

DESCRIPTION OF RELATED ART

The need to remain competitive in cost and performance in the productionof semiconductor devices elevates demand to continually increase thedevice density of integrated circuits. And, to achieve higher degrees ofintegration with the miniaturization in semiconductor integratedcircuitry, robust methodologies are required to reduce the scale of thecircuit pattern formed on the semiconductor substrate. These trends andrequirements impose ever-increasing challenges on the ability totransfer the circuit pattern from one layer to another layer.

Photolithography is a mainstay technique used to manufacturesemiconductor integrated circuitry by transferring geometric shapes andpatterns on a mask to the surface of a semiconductor wafer. Inprinciple, a light sensitive material is exposed to patterned light toalter its solubility in a developing solution. Once imaged anddeveloped, the portion of the light sensitive material that is solublein the developing chemistry is removed, and the circuit pattern remains.

Furthermore, to advance optical lithography, as well as accommodate thedeficiencies thereof, continual strides are being made to establishalternative patterning strategies to equip the semiconductormanufacturing industry for sub-30 nm technology nodes. OpticalLithography (193i) in conjunction with multiple patterning, EUV (ExtremeUltraviolet) Lithography, and DSA (Direct Self Assembly) patterning areconsidered to be some of the promising candidates that are beingevaluated to meet the rising demands for aggressive patterning.Accompanying the increasing complexity of both current and advancedpatterning schemes, a host of materials are used that further impose anever-increasing burden on etch selectivity and the ability toselectively remove one material relative to another.

Advanced patterning schemes utilize multi-layer masks of variouscompositions, whether it is to improve mask budget or prepare a mandrelfor altering topography for multi-pattern formation. Such multi-layermasks include crystalline and amorphous silicon, amorphous carbon,silicon oxide (SiO_(x)), silicon nitride (SiN_(y)), silicon oxynitride(SiO_(x)N_(y)), silicon-containing anti-reflective coating (SiARC),among others. Depending on the process flow and patterning scheme,subsequent etch steps can be used to etch or remove one materialrelative to another. For example, it may be desirable to selectivelyremove SiARC or silicon oxynitride (SiO_(x)N_(y)) with respect to othermaterials/films, such as organic dielectric layers (ODL), crystallineand amorphous silicon, amorphous carbon, silicon dioxide (SiO_(x)),silicon nitride (SiN_(y)).

Current removal techniques include the application of a wet etchchemistry to the workpiece, which has inherent disadvantages due to theetch mechanism. Significant limitations of wet processes include pooretch selectivity of the material to be removed with respect to othermaterials present on the substrate, including silicon oxide (SiO_(x))and silicon nitride (SiN_(y)), among others. In addition, wet processessuffer from pattern damage and defectivity, which constricts accurate(targeted), clean, and selective material etch. Furthermore, dry plasmaprocesses have been explored. However, such processes induce patterndamage. Thus, it is imperative that new systems and processes aredeveloped to enable clean, selective, targeted, and relatively fastremoval of various materials used in patterning schemes, among otherapplications.

SUMMARY OF THE INVENTION

Embodiments of the invention relate to a dry non-plasma treatment systemand method for treating a substrate, and more particularly to a drynon-plasma treatment system and method for chemical and thermaltreatment of a substrate. Additional embodiments include selective,gas-phase, non-plasma etching of various materials.

According to one embodiment, a method for the dry removal of a materialon a microelectronic workpiece is described. The method includesreceiving a workpiece having a surface exposing a target layer to be atleast partially removed, placing the workpiece on a workpiece holder ina dry, non-plasma etch chamber, and selectively removing at least aportion of the target layer from the workpiece. The selective removalincludes operating the dry, non-plasma etch chamber to perform thefollowing: exposing the surface of the workpiece to a chemicalenvironment at a first setpoint temperature in the range of 35 degreesC. to 100 degrees C. to chemically alter a surface region of the targetlayer, and then, elevating the temperature of the workpiece to a secondsetpoint temperature at or above 100 degrees C. to remove the chemicallytreated surface region of the target layer.

According to another embodiment, a system for the dry removal of amaterial on a microelectronic workpiece. The system includes a processchamber for processing a workpiece in a non-plasma, vacuum environment,a workpiece holder arranged within the process chamber, and configuredto support the workpiece, a temperature control system coupled to theworkpiece holder, and configured to control the temperature of theworkpiece holder at two or more setpoint temperatures, a gasdistribution system coupled to the process chamber, and arranged tosupply one or more process gases into the process chamber; and acontroller operably coupled to the temperature control system, andconfigured to control the temperature of the workpiece holder at a firstsetpoint temperature in the range of 35 degrees C. to 100 degrees C.,and adjust and control the temperature of the workpiece holder at asecond setpoint temperature at or above 100 degrees C.

According to yet another embodiment, a method for the dry removal of amaterial on a microelectronic workpiece is described. The methodincludes receiving a workpiece having a surface exposing a target layercomposed of silicon and either (1) organic material or (2) both oxygenand nitrogen, and selectively removing at least a portion of the targetlayer from the workpiece. The selective removal includes exposing thesurface of the workpiece to a chemical environment containing N, H, andF at a first setpoint temperature to chemically alter a surface regionof the target layer, and then, elevating the temperature of theworkpiece to a second setpoint temperature to remove the chemicallytreated surface region of the target layer.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A and 1B illustrate a method of dry removing a layer on aworkpiece according to an embodiment;

FIG. 2 provides a flow chart illustrating a method of dry removing alayer on a substrate according to an embodiment;

FIG. 3 provides a schematic illustration of a dry, non-plasma etchingsystem according to an embodiment; and

FIG. 4 provides a schematic illustration of a workpiece holder accordingto an embodiment.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

In the following description, for purposes of explanation and notlimitation, specific details are set forth, such as a particulargeometry of a processing system, descriptions of various components andprocesses used therein. However, it should be understood that theinvention may be practiced in other embodiments that depart from thesespecific details.

Similarly, for purposes of explanation, specific numbers, materials, andconfigurations are set forth in order to provide a thoroughunderstanding of the invention. Nevertheless, the invention may bepracticed without specific details. Furthermore, it is understood thatthe various embodiments shown in the figures are illustrativerepresentations and are not necessarily drawn to scale.

Various operations will be described as multiple discrete operations inturn, in a manner that is most helpful in understanding the invention.However, the order of description should not be construed as to implythat these operations are necessarily order dependent. In particular,these operations need not be performed in the order of presentation.Operations described may be performed in a different order than thedescribed embodiment. Various additional operations may be performedand/or described operations may be omitted in additional embodiments.

As used herein, the term “radiation sensitive material” means andincludes photosensitive materials such as photoresists.

As used herein, the term “non-plasma” generally means that plasma is notformed in the space proximate the workpiece being treated. While theproducts of plasma can be introduced from a remote location to theenvironment proximate the workpiece being treated, plasma is notactively generated by an electromagnetic field adjacent the workpiece.

“Workpiece” as used herein generically refers to the object beingprocessed in accordance with the invention. The workpiece may includeany material portion or structure of a device, particularly asemiconductor or other electronics device, and may, for example, be abase substrate structure, such as a semiconductor wafer or a layer on oroverlying a base substrate structure such as a thin film. The workpiecemay be a conventional silicon workpiece or other bulk workpiececomprising a layer of semi-conductive material. As used herein, the term“bulk workpiece” means and includes not only silicon wafers, but alsosilicon-on-insulator (“SOI”) substrates, such as silicon-on-sapphire(“SOS”) substrates and silicon-on-glass (“SOG”) substrates, epitaxiallayers of silicon on a base semiconductor foundation, and othersemiconductor or optoelectronic materials, such as silicon-germanium,germanium, gallium arsenide, gallium nitride, and indium phosphide. Theworkpiece may be doped or undoped. Thus, the workpiece is not intendedto be limited to any particular base structure, underlying layer oroverlying layer, patterned or un-patterned, but rather, is contemplatedto include any such layer or base structure, and any combination oflayers and/or base structures. The description below may referenceparticular types of workpieces, but this is for illustrative purposesonly and not limitation.

As noted above, advanced methodologies are required to address thechallenges and meet the demands for aggressive patterning at sub 30 nmtechnology nodes. And, as also noted, these methodologies present theirown set of challenges, which manifest as issues with etch selectivity,rate, profile control, etc. The ability to successfully integratepatterning schemes with highly selective etch processes is paramount torobust pattern transfer.

As an example, once the circuit pattern is initially formed, thepatterned material, whether it be a photosensitive material patternedusing optical lithography, a mechanically imprinted patterned layer, ordirect self-assembled layer, among other things, serves as a protectivelayer that masks some regions of the semiconductor substrate, whileother regions are exposed to permit transfer of the circuit pattern toan underlying layer utilizing a dry etching process, such as a plasmaetch process. In order to increase mask budget and implementmulti-patterning techniques, multi-layer mask schemes can beimplemented, including bi-layer masks or tri-layer masks.

As previously noted, advanced patterning schemes utilize multi-layermasks of various compositions. Such multi-layer masks includecrystalline and amorphous silicon, amorphous carbon, silicon oxide(SiO_(x)), silicon nitride (SiN_(y)), silicon oxynitride (SiO_(x)N_(y)),silicon-containing anti-reflective coating (SiARC), among others.Depending on the process flow and patterning scheme, subsequent etchsteps can be used to etch or remove one material relative to another.For example, it may be desirable to selectively remove SiARC or siliconoxynitride (SiO_(x)N_(y)) with respect to other materials/films, such asorganic dielectric layers (ODL), crystalline and amorphous silicon,amorphous carbon, silicon dioxide (SiO_(x)), silicon nitride (SiN_(y)).

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIGS. 1A,1B, and 2 illustrate a method for the dry removal of a material on amicroelectronic workpiece according to an embodiment. The method ispictorially illustrated in FIGS. 1A and 1B, and presented by way of aflow chart 200 in FIG. 2. As presented in FIG. 2, the flow chart 200begins in 210 with receiving a workpiece 100 having a surface exposing atarget layer to be at least partially removed.

As shown in FIG. 1A, the workpiece 100 can include a patterned mask 120overlying a film stack 110, including one or more layers 112, 114, 116to be etched or patterned. The patterned mask 120 can define an openfeature pattern overlying one or more additional layers. The workpiece100 further includes device layers. The device layers can include anythin film or structure on the workpiece into which a pattern is to betransferred. Furthermore, the patterned mask 120 can include a patternedlayer 122, and a target layer 124 to be removed.

The workpiece 100 can include a bulk silicon substrate, a single crystalsilicon (doped or un-doped) substrate, a semiconductor-on-insulator(SOI) substrate, or any other semiconductor substrate containing, forexample, Si, SiC, SiGe, SiGeC, Ge, GaAs, InAs, InP, as well as otherIII/V or II/VI compound semiconductors, or any combination thereof(Groups II, III, V, VI refer to the classical or old IUPAC notation inthe Periodic Table of Elements; according to the revised or new IUPACnotation, these Groups would refer to Groups 2, 13, 15, 16,respectively). The workpiece 100 can be of any size, for example, a 200mm (millimeter) substrate, a 300 mm substrate, a 450 mm substrate, or aneven larger substrate. The device layers can include any film or devicestructure into which a pattern can be transferred.

In 220, at least a portion of the target layer 124 is selectivelyremoved from the workpiece 100. For example, the target layer 124 can beselectively removed relative to the patterned layer 122 and layer 116 offilm stack 110. The selective removal can be performed by placing theworkpiece 100 in a single chamber, dry, non-plasma etch system, such asthe system to be described in FIG. 3 or the system described in U.S.Pat. No. 7,718,032, entitled “Dry non-plasma treatment system and methodof using”, or a tandem chamber, dry, non-plasma etch system, such as thesystem described in U.S. Pat. No. 7,029,536, entitled “Processing systemand method for treating a substrate” or U.S. Pat. No. 8,303,716,entitled “High throughput processing system for chemical treatment andthermal treatment and method of operating”; the entire contents of whichare herein incorporated by reference.

According to one embodiment, the selective removal is performed byexposing the surface of the workpiece to a chemical environmentcontaining N, H, and F at a first setpoint temperature to chemicallyalter a surface region of the target layer, and then, elevating thetemperature of the workpiece to a second setpoint temperature to removethe chemically treated surface region of the target layer. The targetlayer 124 can include a layer composed of silicon and either (1) organicmaterial or (2) both oxygen and nitrogen.

For example, the target layer 124 can include silicon oxynitride(SiO_(x)N_(y)), wherein x and y are real numbers greater than zero.Furthermore, the target layer 124 can include a silicon-containinganti-reflective coating (ARC) layer. The target layer can have a siliconcontent less than or equal to 20% by weight. Alternatively, the targetlayer can have a silicon content greater than 20% by weight.Alternatively yet, the target layer can have a silicon content in excessof 40% by weight. As an example, the target layer 124 can include asilicon-containing anti-reflective coating (ARC) having a siliconcontent approximately equal to 17% by weight. As another example, thetarget layer 124 can include a silicon-containing anti-reflectivecoating (ARC) having a silicon content approximately equal to 43% byweight.

During the exposing, select surfaces of the workpiece, including exposedsurfaces of the target layer 124, are chemically treated by thegas-phase chemical environment. The inventors have observed the chemicalalteration of these surface layers to proceed in a self-limiting manner,i.e., the surface is exposed to the chemical environment for apre-determined amount of time, and the chemical alteration proceeds to aself-limiting depth. A specific material can be targeted and apre-determined depth can be achieved by selecting various processparameters, including the processing pressure for the chemicalenvironment, the temperature of the workpiece, the temperature of theworkpiece holder, the temperature of other chamber components, thecomposition of the chemical environment, and the absolute and relativeflow rates of the gas-phase constituents into the chamber. Uponelevation of the temperature of the workpiece, the chemically alteredregion of select surfaces of the target layer 124 is volatilized andremoved.

As described above the temperature of the workpiece holder, orworkpiece, can be selected to selectively remove one material relativeto another. In one example, to selectively remove a layer composed ofsilicon and organic material, relative to silicon oxide, siliconnitride, crystalline silicon, amorphous silicon, amorphous carbon, andorganic materials, the first setpoint temperature of the workpieceholder, or workpiece, can range from 50 degrees C. to 100 degrees C., or60 degrees C. to 90 degrees C., or preferably from 70 degrees C. to 90degrees C. In another example, to selectively remove a layer composed ofsilicon and both oxygen and nitrogen (e.g., SiO_(x)N_(y), x and y beingreal numbers greater than zero), relative to silicon oxide, siliconnitride, crystalline silicon, amorphous silicon, amorphous carbon, andorganic materials, the first setpoint temperature of the workpieceholder, or workpiece, can range from 35 degrees C. to 100 degrees C., orpreferably from 40 degrees C. to 100 degrees C. (it can depend on thestack of materials being exposed). In yet another example, toselectively remove a layer composed of SiO_(x), wherein x is a realnumber greater than zero, the first setpoint temperature can range from10 degrees C. to 40 degrees C.

The chemical environment can contain HF, NF₃, F₂, NH₃, N₂, or H₂, or acombination of two or more thereof. The chemical environment can furthercontain a noble element. In other embodiments, the chemical environmentcan contain an excited specie, a radical specie, or a metastable specie,or any combination of two or more thereof. For example, the dry,non-plasma etch chamber includes a remote plasma generator or remoteradical generator arranged to supply the dry, non-plasma etch chamberwith excited, radical or metastable specie of F, N, or H. The processingpressure can range from 500 mTorr to 2 Torr.

Thereafter, the targeted chemically altered surface layers are desorbedby elevating the temperature from the first setpoint temperature to thesecond setpoint temperature, which may take place in the same chamber ora separate chamber. The second setpoint temperature can range from 100degrees C. to 225 degrees C., or preferably, the second setpointtemperature ranges from 160 degrees C. to 190 degrees C.

In one example, the inventors have demonstrated the selective removal ofa target layer composed of a SiO_(x)N_(y), x and y being real numbersgreater than zero, wherein an etch selectivity of the target layerrelative to silicon oxide, silicon nitride, crystalline silicon,amorphous silicon, amorphous carbon, and organic materials exceededunity. SiO_(x)N_(y) can be completely removed with little to no patternlift-off or damage, and Si substrate loss. As an example, three (3), ten(10) second cycles at a first setpoint temperature of 85 degrees C., anda second setpoint temperature of 100 degrees C. has achieved the aboveidentified results.

In another example, the inventors have demonstrated the selectiveremoval of a target layer composed of a silicon-containinganti-reflective coating (ARC) having a silicon content approximatelyequal to 17% by weight, or approximately equal to 43% by weight, whereinan etch selectivity of the target layer relative to silicon oxide,silicon nitride, crystalline silicon, amorphous silicon, amorphouscarbon, and organic materials exceeded 10-to-1. SiARC can be completelyremoved with little to no pattern lift-off or damage, little to nopattern “wiggle”, and Si substrate loss.

Furthermore, the steps of exposing and elevating can be alternatinglyand sequentially performed. From one step to the next, or one cycle tothe next, any one or more of the process parameters, including theprocessing pressure for the chemical environment, the temperature of theworkpiece, the temperature of the workpiece holder, the temperature ofother chamber components, the composition of the chemical environment,and the absolute and relative flow rates of the gas-phase constituentsinto the chamber, can be adjusted.

According to another embodiment, the workpiece 100 is placed on aworkpiece holder in a single chamber, dry, non-plasma etch system, suchas the system described in FIG. 3. The single chamber, dry, non-plasmaetch system is operated to perform the following: (1) exposing thesurface of the workpiece to a chemical environment at a first setpointtemperature in the range of 35 degrees C. to 100 degrees C. tochemically alter a surface region of the target layer, and (2) then,elevating the temperature of the workpiece to a second setpointtemperature at or above 100 degrees C. to remove the chemically treatedsurface region of the target layer. The first setpoint temperature canrange from 35 degrees C. to 100 degrees C., or 70 degrees C. to 90degrees C., and the second setpoint temperature can range from 110degrees C. to 225 degrees C.

The first setpoint temperature can be established by flowing a heattransfer fluid through the workpiece holder at a first fluid setpointtemperature. The second setpoint temperature can be established byflowing the heat transfer fluid through the workpiece holder at a secondfluid setpoint temperature. In addition to flowing the heat transferfluid through the workpiece holder at the second fluid setpointtemperature, the workpiece holder can be heated by coupling electricalpower to at least one resistive heating element embedded within theworkpiece holder. Alternatively, in addition to flowing the heattransfer fluid through the workpiece holder at the second fluid setpointtemperature, heating the workpiece holder using at least one other heatsource separate from the workpiece holder.

According to another embodiment, a system 300 for the dry removal of amaterial on a microelectronic workpiece 325 is shown in FIG. 3. Thesystem 300 includes a process chamber 310 for processing workpiece 325in a non-plasma, vacuum environment, a workpiece holder 320 arrangedwithin the process chamber 310, and configured to support the workpiece325, a temperature control system 350 coupled to the workpiece holder320, and configured to control the temperature of the workpiece holder320 at two or more setpoint temperatures, a gas distribution system 330coupled to the process chamber 310, and arranged to supply one or moreprocess gases into the process chamber 310, and a controller 360operably coupled to the temperature control system 350, and configuredto control the temperature of the workpiece holder 320 ranging from 35degrees C. to 250 degrees C. For example, the temperature control system350 can be configured to control the temperature of the workpiece holder320 at a first setpoint temperature in the range of 35 degrees C. to 100degrees C., and adjust and control the temperature of the workpieceholder 320 at a second setpoint temperature at or above 100 degrees C.Alternatively, for example, the temperature control system 350 can beconfigured to control the temperature of the workpiece holder 320 at afirst setpoint temperature in the range of 10 degrees C. to 100 degreesC., and adjust and control the temperature of the workpiece holder 320at a second setpoint temperature at or above 100 degrees C.

The process chamber 310 can include a vacuum pump 340 to evacuateprocess gases from process chamber 310. The process chamber 310 canfurther include a remote plasma generator or remote radical generatorarranged to supply the process chamber with excited, radical ormetastable species, or combinations thereof.

Gas distribution system 330 can include a showerhead gas injectionsystem having a gas distribution assembly, and one or more gasdistribution plates or conduits coupled to the gas distribution assemblyand configured to form one or more gas distribution plenums or supplylines. Although not shown, the one or more gas distribution plenums maycomprise one or more gas distribution baffle plates. The one or more gasdistribution plates further comprise one or more gas distributionorifices to distribute a process gas from the one or more gasdistribution plenums to the process chamber 310. Additionally, one ormore gas supply lines may be coupled to the one or more gas distributionplenums through, for example, the gas distribution assembly in order tosupply a process gas comprising one or more gases. Process gases can beintroduced together as a single flow, or independently as separateflows.

Gas distribution system 330 can further include a branching gasdistribution network designed to reduce or minimize gas distributionvolume. The branching network can remove plenums, or minimize the volumeof gas plenums, and shorten the gas distribution length from gas valveto process chamber, while effectively distributing the process gasacross the diameter of the workpiece 325. In doing so, gases can beswitched more rapidly, and the composition of the chemical environmentcan be changed more effectively.

The volume of the process chamber 310 defining the chemical environment,to which the workpiece 325 is exposed, can be reduced or minimized inorder to reduce or minimize the residence time or time required toevacuate, displace, and replace one chemical environment with anotherchemical environment. The time to displace the chemical environment inthe process chamber 310 can be estimated as the ratio of the processchamber volume to the pumping speed delivered to the process chambervolume by the vacuum pump 340.

Workpiece holder 320 can provide several operational functions forthermally controlling and processing workpiece 325. The workpiece holder320 includes one or more temperature control elements configured toadjust and/or elevate a temperature of the workpiece holder 320.

As shown in FIG. 4, workpiece holder 320 can include at least one fluidchannel 322 to allow flow of a heat transfer fluid there through andalter a temperature of the workpiece holder 320. Workpiece holder 320can further include at least one resistive heating element 324.Multi-zone channels and/or heating elements can be used to adjust andcontrol the spatial uniformity of heating and cooling of workpiece 325.For example, the at least one resistive heating element 324 can includea central-zone heating element and an edge-zone heating element.Additionally, for example, the at least one fluid channel 322 caninclude a central-zone fluid channel and an edge-zone fluid channel. Attemperatures above 200 to 250 degrees C., other heating systems can beused, including infrared (IR) heating, such as lamp heating, etc.

A power source 358 is coupled to the at least one resistive heatingelement 324 to supply electrical current. The power source 358 caninclude a direct current (DC) power source or an alternating current(AC) power source. Furthermore, the at least one resistive heatingelement 324 can be connected in series or connected in parallel.

The at least one resistive heating element 324 can, for example, includea resistive heater element fabricated from carbon, tungsten,nickel-chromium alloy, aluminum-iron alloy, aluminum nitride, etc.Examples of commercially available materials to fabricate resistiveheating elements include Kanthal, Nikrothal, Akrothal, which areregistered trademark names for metal alloys produced by KanthalCorporation of Bethel, Conn. The Kanthal family includes ferritic alloys(FeCrAl) and the Nikrothal family includes austenitic alloys (NiCr,NiCrFe). According to one example, each of the at least one resistiveheating element 324 can include a heating element, commerciallyavailable from Watlow Electric Manufacturing Company (12001 LacklandRoad, St. Louis, Mo. 63146). Alternatively, or in addition, coolingelements can be employed in any of the embodiments.

A heat transfer fluid distribution manifold 352 is arranged to pump andmonitor the flow of heat transfer fluid through the one or more fluidchannels 322. The heat transfer fluid distribution manifold 352 can drawheat transfer fluid from a first heat transfer fluid supply bath 354 ata first heat transfer fluid temperature and/or a second heat transferfluid supply bath 356 at a second heat transfer fluid temperature.Manifold 352 can mix heat transfer fluid from the first and second heattransfer fluid supply baths 354, 356 to achieve an intermediatetemperature. Furthermore, the heat transfer fluid distribution manifold352 can include a pump, a valve assembly, a heater, a cooler, and afluid temperature sensor to controllably supply, distribute, and mix aheat transfer fluid at a predetermined temperature.

In an alternative embodiment, the temperature control system 350 caninclude a hot wall in close proximity to the work piece holder 320. Theworkpiece holder 320 can further include a workpiece clamping systemconfigured to clamp the workpiece to the workpiece holder, and abackside gas supply system configured to supply a heat transfer gas tothe backside of the workpiece.

The heat transfer fluid can include a high temperature fluid having aboiling point exceeding 200 degrees C. For example, the heat transferfluid can include Fluorinert™ FC40 (having a temperature range of −57 to165 dgrees C.), or Fluorinert™ FC70 (having a temperature range of −25to 215 dgrees C.), commercially available from 3M.

Workpiece holder 320 can be monitored using a temperature sensingdevice, such as a thermocouple (e.g. a K-type thermocouple, Pt sensor,etc.) or optical device. Furthermore, the substrate holder temperaturecontrol system 350 may utilize the temperature measurement as feedbackto the workpiece holder 320 in order to control the temperature ofworkpiece holder 320. For example, at least one of a fluid flow rate, afluid temperature, a heat transfer fluid type, a heat transfer fluidpressure, a clamping force, a resistive heater element current orvoltage, a thermoelectric device current or polarity, etc. may beadjusted in order to affect a change in the temperature of workpieceholder 320 and/or the temperature of the workpiece 325.

As noted above, controller 360 is operably coupled to the temperaturecontrol system 350, and configured to control the temperature of variouscomponents in system 300, including the workpiece holder 320, attemperatures ranging from 10 degrees C. to 250 degrees C., or 35 degreesC. to 250 degrees C., or 50 degrees C. to 250 degrees C. For example,under instruction of controller 360, the temperature control system 350can be configured to control the temperature of the workpiece holder 320at a first setpoint temperature in the range of 35 degrees C. to 100degrees C., and adjust and control the temperature of the workpieceholder 320 at a second setpoint temperature at or above 100 degrees C.(see process recipes described above). The temperature control system350 can obtain temperature information from one or more temperaturesensors arranged to measure the temperature of the workpiece holder 320,the workpiece 325, the chamber wall of the process chamber 310, or thetemperature of the gas distribution system 330, among others, andutilize the temperature information to controllably adjust thesetemperatures.

As an example, when changing the temperature of the workpiece holder 320from the first setpoint temperature, in the range of 35 degrees C. to100 degrees C., to the second setpoint temperature, at or above 100degrees C., the fluid temperature of the heat transfer fluid can beadjusted rapidly by changing the ratio of heat transfer fluid drawn fromthe heat transfer fluid supply baths 354, 356. Once within apredetermined range of the targeted second setpoint temperature, the atleast one resistive heating element can be utilized to accuratelycontrol the setpoint temperature. The workpiece holder 320 can bedesigned to have a relatively low thermal mass. For example, thethickness of the holder and material composition of the holder can bedesigned to reduce or minimize the thermal mass of the holder.Furthermore, the at least one fluid channel 322, including the fluidconduits supplying heat transfer fluid to the at least one fluid channel322, can be designed to have low volume in order to change fluidtemperature rapidly. For example, the length and diameter of the fluidchannels and conduits can be designed to reduce or minimize volume(i.e., reduce the time necessary to displace fluid of one temperature,and replace it with fluid of another temperature).

Other chamber components of process chamber 310, including chamberwalls, the gas distribution system 330, etc., can include heating and/orcooling elements to control the temperature thereof. For example, thechamber wall temperature of the process chamber 310 and the temperatureof at least a portion of the gas distribution system can be controlledto a temperature up to 150 degrees C., or within the range 50 degrees C.to 150 degrees C. (preferably, 70 degrees C. to 110 degrees C.).

Although only certain embodiments of this invention have been describedin detail above, those skilled in the art will readily appreciate thatmany modifications are possible in the embodiments without materiallydeparting from the novel teachings and advantages of this invention.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

The invention claimed is:
 1. A method for the dry removal of a materialon a microelectronic workpiece, comprising: receiving a workpieceincluding a film stack and a patterned mask partially overlying the filmstack, wherein the patterned mask includes a patterned layer and atarget layer disposed on the patterned layer such that the target layeris above the patterned layer with the target layer and the patternedlayer each including openings therein such that at least one layer ofthe film stack is exposed through the openings of the target layer andthe patterned layer, and the openings of the target layer and thepatterned layer expose sidewall surfaces of the target layer and thepatterned layer, and wherein the target layer is formed of a differentmaterial than the patterned layer; placing the workpiece on a workpieceholder in a single chamber of a dry, non-plasma etch system, wherein theworkpiece holder comprises a plurality of fluid channels including acentral-zone fluid channel and an edge-zone fluid channel, and theworkpiece holder comprises a plurality of resistive heating elementsincluding a central-zone heating element and an edge-zone heatingelement; and selectively removing at least a portion of the target layerfrom the workpiece by operating the dry, non-plasma etch system toperform the following: exposing the workpiece to a chemical environmentat a first setpoint temperature in the range of 35 degrees C. to 100degrees C. to chemically alter a surface region of the target layer, andthen, elevating the temperature of the workpiece to a second setpointtemperature at or above 100 degrees C. to remove the chemically treatedsurface region of the target layer; wherein the first setpointtemperature is established by coupling electrical power to at least oneof the resistive heating elements and flowing a heat transfer fluidthrough at least one of the fluid channels of the workpiece holder at afirst fluid setpoint temperature, wherein the second setpointtemperature is established by coupling electrical power to at least oneof the resistive heating elements and changing the first fluid setpointtemperature to a second fluid setpoint temperature and flowing the heattransfer fluid through at least one of the fluid channels of theworkpiece holder at the second fluid setpoint temperature, and wherein atemperature of the heat transfer fluid is changed from the first fluidsetpoint temperature to the second fluid setpoint temperature byadjusting a ratio of the heat transfer fluid that is drawn from a firstheat transfer fluid supply bath at a first heat transfer fluidtemperature and a second heat transfer fluid supply bath at a secondheat transfer fluid temperature; wherein the steps of exposing andelevating are repeated alternatingly and sequentially two or more timesso that the target layer is completely removed from the workpiecewithout removing the patterned layer and without removing the at leastone layer of the film stack which is exposed.
 2. The method of claim 1,wherein the first setpoint temperature ranges from 70 degrees C. to 90degrees C., and the second setpoint temperature ranges from 110 degreesC. to 225 degrees C.
 3. The method of claim 1, wherein the steps ofexposing and elevating are performed at a processing pressure rangingfrom 500 mTorr to 2 Torr.
 4. The method of claim 1, wherein the chemicalenvironment contains N, H, and F.
 5. The method of claim 1, wherein thechemical environment contains an excited specie, a radical specie, or ametastable specie, or any combination of two or more thereof.
 6. Themethod of claim 1, wherein the central-zone fluid channel, the edge-zonefluid channel, the central-zone heating element, and an edge-zoneheating element are configured to control heating and cooling of thesurface of the workpiece in a spatial direction along the surface of theworkpiece.
 7. The method of claim 1, wherein, prior to the selectivelyremoving at least a portion of the target layer, the patterned maskdefines one or more openings exposing the film stack, side and topsurfaces of the target layer are exposed, and side surfaces of thepatterned layer are exposed.
 8. The method of claim 7, wherein thetarget layer comprises one of SiO_(x)N_(y), x and y being real numbersgreater than zero, a silicon-containing anti-reflective coating (ARC),or a composition of silicon and an organic material; and wherein thepatterned layer comprises one of silicon oxide, silicon nitride,crystalline silicon, amorphous silicon, amorphous carbon, or an organicmaterial.
 9. The method of claim 8, wherein the chemical environmentincludes at least one of N, F and H.
 10. A method for the dry removal ofa material on a microelectronic workpiece, comprising: receiving aworkpiece including a film stack and a patterned mask partiallyoverlying the film stack, wherein the patterned mask includes apatterned layer and a target layer disposed on the patterned layer suchthat the target layer is above the patterned layer with the target layerand the patterned layer each including openings therein such that atleast one layer of the film stack is exposed through the openings of thetarget layer and the patterned layer, and the openings of the targetlayer and the patterned layer expose sidewall surfaces of the targetlayer and the patterned layer, and wherein the target layer is formed ofa different material than the patterned layer; placing the workpiece ona workpiece holder in a single chamber of a dry, non-plasma etch system;and selectively removing at least a portion of the target layer from theworkpiece by operating the dry, non-plasma etch system to perform thefollowing: exposing the workpiece to a chemical environment containing agaseous mixture that includes N, H, and F at a first workpiece setpointtemperature in the range of 35 degrees C. to 100 degrees C. tochemically alter a surface region of the target layer and a depth withinthe target layer such that, after the exposing, the target layerincludes a chemically altered surface region and a chemically altereddepth within the target layer, wherein the N, H, and F are introducedinto the single chamber simultaneously; then, elevating the temperatureof the workpiece to a second setpoint temperature at or above 100degrees C. to volatize and selectively remove the chemically alteredsurface region and the chemically altered depth of the target layerwithout removing the patterned layer and the film stack; wherein thesteps of exposing and elevating are repeated alternatingly andsequentially two or more times so that the target layer is completelyremoved from the workpiece without removing the patterned layer andwithout removing the at least one layer of the film stack which isexposed.
 11. The method of claim 10, wherein the dry, non-plasma etchsystem includes a showerhead gas injection system coupled to the singlechamber, and the step of exposing comprises using the showerhead gasinjection system to introduce the N, H, and F together into the singlechamber as a single flow.
 12. The method of claim 10, wherein the dry,non-plasma etch system includes a showerhead gas injection systemcoupled to the single chamber, and the step of exposing comprises usingthe showerhead gas injection system to introduce the N, H, and Fsimultaneously into the single chamber as separate flows.
 13. The methodof claim 10, wherein, prior to the selectively removing at least aportion of the target layer, the patterned mask defines one or moreopenings exposing the film stack, side and top surfaces of the targetlayer are exposed, and side surfaces of the patterned layer are exposed.14. The method of claim 13, wherein the target layer comprises one ofSiO_(x)N_(y), x and y being real numbers greater than zero, asilicon-containing anti-reflective coating (ARC), or a composition ofsilicon and an organic material; and wherein the patterned layercomprises one of silicon oxide, silicon nitride, crystalline silicon,amorphous silicon, amorphous carbon, or an organic material.
 15. Themethod of claim 10, wherein the target layer is completely removed afterthree ten second cycles of repeating the exposing and elevating.